JPH06189467A - Voltage control device for vehicle alternator - Google Patents

Abstract

(57) [Abstract] [Purpose] In a voltage control device for a vehicle generator, the current value to the power transistor for controlling the charge lamp lighting is substantially reduced, and a low rated power transistor can be applied. And a voltage control device with reduced price. [Structure] The drive circuit 107 supplies an ON signal to the power transistor 101 based on the terminal voltage of the battery 2. By controlling the transistor 101, the current to the field winding 13 is adjusted and the voltage of the battery 2 is controlled. The alarm circuit 106 supplies an alarm signal d to the drive circuit 105 based on the voltage change of the terminal L such as disconnection of the battery 2 terminal and the voltage change of the winding 11c. The voltage detection circuit 104 supplies signals b and c to the drive circuit 105 based on the signal a from the terminal L. The drive circuit 105 supplies the control signal e to the power transistor 103 based on the signals b, c, and d.
As a result, the transistor 103 is driven intermittently,
The flowing current value is reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a voltage control device for a vehicle alternator.

[0002]

2. Description of the Related Art In a vehicle charging generator, the rotational force of a driving torque generated by an internal combustion engine is transmitted to a rotor via a belt, a rotating field winding is rotated, and a rotating magnetic field is generated. . Then, the rotating magnetic field rectifies the current generated in the armature winding, and the rectified current charges the battery. In this case, the voltage controller regulates the current to the field winding so that the battery is charged with a constant voltage. By the way, the voltage control device of the vehicle alternator also controls the lighting of the charge lamp by controlling the on / off of the power transistor. Regarding the lighting control of the charge lamp, for example, there is a voltage adjusting device for a charging generator described in Japanese Patent Application Laid-Open No. 63-110924. The voltage adjusting device described in this publication lights the charging indicator lamp and issues a warning to the driver when the power generation operation is stopped due to contact failure or the like during vehicle operation.

[0003]

In the above voltage control device for a vehicle alternator, the current flowing through the charge lamp is usually about 0.3 A, but at the start of energization, as shown in FIG. , A large inrush current of 5 to 6 A flows. Therefore, the power transistor for controlling the charge lamp lighting needs to be rated so as not to be thermally destroyed by the inrush current. For this reason, conventionally, a large power transistor of about 2 mm square has to be used, resulting in a large space and price required for installation.

An object of the present invention is to reduce a current flowing to a power transistor for controlling charge lamp lighting in a voltage control device for a vehicle generator so that a low rated power transistor can be applied. It is to realize a voltage control device with a reduced installation area and cost.

[0005]

In order to achieve the above object, the present invention is configured as follows. In a voltage control device for a vehicle AC generator that has a field winding attached to a rotor and an armature winding attached to a stator, detects a charging voltage of the battery, Field winding current control means for controlling the current flowing through the field winding so that the battery is charged with a constant voltage, charging warning means connected to the battery via the opening / closing means, and the charging warning means. Connected to the charging alarm means, switching means for performing a current passing and stopping operation to the charging alarm means, a current detecting means for detecting the current flowing through the charging alarm means and outputting a signal corresponding to the detected current, at least the current Drive means for driving the switching means in response to the output signal from the detecting means and controlling the current passing and stopping operation of the switching means to change the conduction ratio.

[0006] Preferably, in the voltage control device for the vehicle alternator, it is detected that a current is passed to the charging alarm means and a current is passed to the armature winding, and the detection signal is driven by the drive means. Further comprising a flow detection means for supplying
The drive means is configured to control the operation of the switching means based on the detection signal from the flow detection means and the output signal from the current detection means. Further, preferably, in the current control device for the vehicle alternator, the current detection unit separates the current flowing through the charging alarm unit into at least two stages according to the value, and outputs a signal corresponding to this stage. , Is output as a signal corresponding to the detected current.

Further, preferably, in the voltage control device for the vehicle alternator, the current detecting means is configured to output a digital signal corresponding to a current flowing through the charging alarm means. Further, preferably, in the voltage control device of the vehicle alternator, the current detection means,
A first comparator that compares a voltage value corresponding to a current flowing through the charging alarm means with a first reference voltage is compared with the above-mentioned voltage value and a second reference voltage that is smaller than the first reference voltage. And a second comparator, wherein the driving means has a 0.1% when the voltage value is higher than the first reference voltage.
An on-duty signal of ˜1.0% is supplied to the switching means, and when the voltage value is smaller than the first reference voltage and larger than the second reference voltage, 20% to 3%.
A 0% on-duty signal is supplied to the switching means, and when the voltage value is smaller than the second reference voltage, an on-duty signal of about 100% is supplied to the switching means.

[0008]

The current detecting means detects the current flowing through the charging alarm means. If the detected current value is larger than a predetermined value, the drive means controls the current passage and the stop operation to reduce the current conduction ratio of the switching means, and a large current does not flow to the switching means. To control. As a result, even if an inrush current tries to flow at the start of energization, the conduction ratio is changed and a large current does not flow to the switching means. Therefore, the rating of the switching means can be reduced, and the installation area and price can be reduced.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A voltage control device for a vehicle generator according to an embodiment of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a schematic configuration diagram of a voltage control device for a vehicle generator. In FIG. 1, 1 is a vehicle generator,
This vehicle generator 1 includes three-phase windings 11a, 11b, 11
The armature winding 11 is composed of c, the three-phase full-wave rectifier 12 is composed of six Zener diodes 12a to 12f, the field winding 13 and the voltage controller 10. 2 is a battery, and the battery 2 is charged by the generator 1. Reference numeral 3 denotes an ignition switch (opening / closing means), and the ignition switch 3 electrically connects the charge lamp (charging alarm means) 4 and the battery 2. The voltage control device 10 includes a field control power transistor 101 that controls a current flowing through the field winding 13.
Diode 102, L terminal voltage detection circuit (corresponding to current detection means) 104, charge lamp drive power transistor drive circuit (drive means) 105, charge lamp drive power transistor (switching means) 103, alarm circuit (current detection means) ) 106 and a drive circuit 107. The power transistor 101 and the drive circuit 107 constitute field winding current control means.

The drive circuit 107 detects the terminal voltage of the battery 2 and supplies an ON signal to the base of the field control power transistor 101 according to the detected terminal voltage.
Then, by the on / off control of the power transistor 101, the current flowing in the field winding 13 is adjusted, and the terminal voltage of the battery 2 is controlled to be constant. Alarm circuit 106
Detects the disconnection of the terminal of the battery 2 by the voltage change of the terminal L, and detects the non-power generation state of the one-phase armature winding 1
The alarm signal d, which is detected by the change in the terminal voltage of 1c and means that the charge lamp is turned on, is supplied to the drive circuit 105.
Further, the voltage detection circuit 104 supplies signals b and c (digital signals) described later to the drive circuit 105 based on the signal a from the terminal L. The drive circuit 105 outputs the signal b,
An on / off control signal e is supplied to the base of the power transistor 103 based on c and d. The emitter of the power transistor 103 is grounded, and the collector is connected to the terminal L.

FIG. 2 is a circuit diagram of the voltage detection circuit 104. In FIG. 2, the negative pole of the reference voltage source 1044 is grounded and the positive poles thereof are resistors 1041, 1042,
It is grounded via 1043. In addition, the comparator 104
The voltage signal f at the midpoint of connection between the resistors 1041 and 1042 is supplied to the inverting input terminal of 5, and the voltage signal a at the terminal L is supplied to the non-inverting input terminal. Then, the output signal b from the comparator 1045 is supplied to the transistor drive circuit 105. Further, the voltage signal g at the connection midpoint between the resistors 1042 and 1043 is supplied to the inverting input terminal of the comparator 1046, and the non-inverting input terminal is
The voltage signal a at the terminal L is supplied. The output signal c from the comparator 1046 is the transistor drive circuit 1
It is supplied to 05.

In the voltage detection circuit 104, when the voltage signal a is larger than the voltage signal f in the first mode, that is, when the charge lamp 4 is short-circuited and a current of ten and a dozen A flows, the comparator 1045 and the comparison circuit are compared. Both the output signals b and c of the container 1046 become "1" (high level). Next, in the second mode, when the voltage signal a is smaller than the voltage signal f and larger than the voltage signal g, that is, at the initial lighting of the charge lamp 4, the lamp resistance is low and 4 to 5 A.
When the inrush current flows in, the voltage signal b is "0".
(Low level), the voltage signal c becomes "1". further,
In the third mode, when the voltage signal a is smaller than the voltage signal g, that is, in the normal lighting state, both the voltage signals b and c are “0”.

FIG. 3 is a circuit diagram of the power transistor driving circuit 105 for driving the charge lamp. In FIG. 3, reference numeral 1051 denotes a 0.4% on-duty signal generator having a cycle of about 500 μsec.
The output signal of 1 is supplied to one input terminal of the AND circuit 1053. The voltage signal b is supplied to the other input terminal of the AND circuit 1053. The voltage signal b is N
It is supplied to one input terminal of the AND circuit 1055 and one input terminal of the AND circuit 1060 via the OT circuit 1054. Further, the voltage signal c is supplied to the other input terminal of the AND circuit 1055, and the NOT circuit 10
It is supplied to the other input terminal of the AND circuit 1060 via 59.

Reference numeral 1052 denotes a cycle of about 500 μsec, 25
% On-duty signal generator, and the output signal of this signal generator 1052 is supplied to one input terminal of the AND circuit 1056. The output signal of the AND circuit 1055 is supplied to the other input terminal of the AND circuit 1056. The AND circuits 1053, 1056,
The output signal of 1060 is supplied to the input terminal of the OR circuit 1057. 1058 is an AND circuit, and this AND
The signal d is supplied to one input terminal of the circuit 1058, and the output signal of the OR circuit 1057 is supplied to the other input terminal. Then, the signal e is output from the AND circuit 1058.
Are supplied to the base of the power transistor 103.

In the circuit of FIG. 3, it is assumed that the switch 3 is closed and the alarm circuit 106 sets the alarm signal d, which means lighting of the charge lamp, to "1". At this time, in the case of the first mode state, the signals b and c are
Are both "1", and the output levels of the AND circuits 1055, 1056 and 1060 are "0". Therefore A
The output signal of the ND circuit 1053 becomes a signal generated from the duty signal generator 1051, and this signal is ORed.
The output signal e is output via the circuit 1057 and the AND circuit 1058. As a result, the power transistor 103
Are driven with 0.4% on-duty.

Next, in the second mode, the voltage signal b is "0" and the voltage signal c is "1". In this case, the output signals of the AND circuits 1053 and 1060 are "
The output signal of the AND circuit 1055 becomes "1".
Becomes Therefore, the output signal of the AND circuit 1056 is 2 output from the duty signal generator 1052.
It becomes a 5% on-duty signal. The on-duty signal is applied to the OR circuit 1057 and the AND circuit 10
It becomes an output signal e via 58. As a result, the power transistor 103 is driven with a 25% on-duty.

Further, in the third mode, both the voltage signals b and c are "0". In this case, A
The output signals of the ND circuits 1053, 1055, and 1056 are "0", and the output signal of the AND circuit 1060 is "1". Therefore, the output signal of the AND circuit 1058 also becomes "1", and the power transistor 103
Remains on.

FIG. 4 is a waveform diagram of a current flowing through the power transistor 103 in the second and third mode states, where the vertical axis is the passing current IL (A) and the horizontal axis is the time (ms). 5 is an average current waveform diagram of the current shown in FIG. As shown in FIG. 4, if the duty control of the power transistor 103 is performed as described above, the current flowing through the power transistor 103 flows at a 25% on-duty ratio until it decreases to the current value Ig corresponding to the voltage signal g. As a result, as shown in FIG. 5, the average inrush current is reduced to about 25% of the average inrush current value in the conventional voltage controller shown in FIG. In the inrush current waveform in the conventional voltage control device shown in FIG. 6, when the charge lamp 4 is in a cold state at the start of energization, the resistance value of the charge lamp 4 is low and an inrush current of 5 to 6 A flows.

Therefore, according to the above-described embodiment of the present invention, the rating of the charge lamp driving power transistor 103 is set to about 25% of the conventional rating, and the charge lamp driving power transistor 103 can be reduced to a size of about 1 mm square. It is possible to reduce the price of the voltage control device 10.

Various transistors such as a power MOSFET can be applied to the power transistor 103 as the switching means. The duty signal generator 1051 is not limited to the 0.4% on-duty signal, and may be an on-duty signal in the range of 0.1 to 1.0%. Further, the duty signal generator 1052 is not limited to the 25% on-duty signal, and may be an on-duty signal within the range of 20 to 30%.

Further, in the above embodiment, the power transistor 103 is intermittently turned on and off by using signal generators having different duty ratios.
Instead of 051 and 1052, signal generators having different frequencies may be arranged to drive the power transistor 103 intermittently. Further, in the above-described embodiment, three types of modes are discriminated according to the value of the voltage signal a of the terminal L, but four or more types of modes are discriminated and further according to the discriminated modes, On / off of the power transistor 103 may be finely controlled. Further, the determined mode may be transmitted to an external controller or the like.

[0022]

Since the present invention is constructed as described above, it has the following effects. In a voltage control device for a vehicle AC generator that has a field winding and an armature winding and charges a battery, the current flowing through the field winding is controlled so that the battery is charged at a constant voltage. Field winding current control means, charging warning means connected to the battery, switching means for passing and stopping current to the charging warning means, and a signal corresponding to the current flowing through the charging warning means. A current detecting means and a driving means for controlling a current passing and a stopping operation of the switching means to change a conduction ratio according to an output signal from the current detecting means. If the detected current value is larger than the predetermined value,
The drive means controls the current passing and the stopping operation to reduce the current conduction ratio of the switching means so that a large current does not flow into the switching means. As a result, even if an inrush current tries to flow at the start of energization, the conduction ratio is changed and a large current does not flow to the switching means. Therefore, the rating of the switching means can be reduced, and the voltage control device with a reduced installation area and cost can be realized.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.

FIG. 2 is a circuit diagram of a voltage detection circuit in the example of FIG.

FIG. 3 is a circuit diagram of a transistor drive circuit in the example of FIG.

FIG. 4 is a waveform diagram of an inrush current in the example of FIG.

5 is an average current waveform diagram of an inrush current in the example of FIG.

FIG. 6 is a waveform diagram of an inrush current in the conventional voltage control device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Generator 2 Battery 3 Ignition switch 4 Charge lamp 10 Voltage control device 11 Armature winding 11a-11c Three-phase winding 12 Three-phase full-wave rectifier 12a-12c Zener diode 13 Field winding 101 Field-control power transistor 102 Diode 103 Charge lamp driving power transistor 104 Voltage detection circuit 105 Charge lamp driving transistor driving circuit 106 Alarm circuit 107 Field control transistor driving circuit 1041-1043 Resistors 1045, 1046 Comparator 1051, 1052 Duty signal generator 1053, 1055 AND circuit 1056, 1058 AND circuit 1054, 1059 NOT circuit 1057 OR circuit

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yuji Maeda 2520, Takaba, Katsuta-shi, Ibaraki Hitachi, Ltd. Automotive Equipment Division (72) Inventor Sakae Hikita 2477 Kashima Yatsu, Katsuta, Ibaraki 3 Within Hitachi Automotive Engineering Co., Ltd.

Claims (5)

[Claims] 1. A voltage control device for a vehicle alternator for charging a battery, comprising: a field winding mounted on a rotor; and an armature winding mounted on a stator. Field winding current control means for detecting the voltage and controlling the current flowing through the field winding so that the battery is charged with a constant voltage, and charging alarm means connected to the battery via the opening / closing means. A switching means which is connected to the charging warning means and which carries out and stops a current passing through the charging warning means; and a current flowing through the charging warning means is detected and a signal corresponding to the detected current is outputted. Current detection means, at least in accordance with the output signal from the current detection means,
A voltage control device for a vehicle alternator, comprising: driving means for driving the switching means and controlling current passing and stopping operations of the switching means to change a conduction ratio. 2. The voltage control device for a vehicle alternator according to claim 1, wherein it is detected that a current is passed to the charging alarm means and a current is passed to an armature winding,
An operation of the switching means based on a detection signal from the current detection means and an output signal from the current detection means is further provided, the current flow detection means supplying a detection signal to the drive means. A voltage control device for a vehicle alternator, which controls the voltage. 3. The current control device for a vehicle alternator according to claim 1, wherein the current detection unit separates the current flowing through the charging alarm unit into at least two stages according to the value of the current. Is output as a signal corresponding to the detected current, a voltage control device for a vehicle AC generator. 4. The voltage control device for a vehicle AC generator according to claim 1, wherein the current detection means outputs a digital signal corresponding to a current flowing through the charging alarm means. Machine voltage control device. 5. The voltage control device for a vehicle alternator according to claim 1, wherein the current detecting means compares a voltage value corresponding to a current flowing through the charging alarm means with a first reference voltage. And a second comparator that compares the voltage value with a second reference voltage that is smaller than the first reference voltage.
When the voltage value is higher than the reference voltage, the on-duty signal of 0.1% to 1.0% is supplied to the switching means, and the voltage value is lower than the first reference voltage and the second voltage is applied.
When the voltage value is lower than the second reference voltage, the on-duty signal of 20% to 30% is supplied to the switching means. When the voltage value is lower than the second reference voltage, the on-duty signal of about 100% is supplied. A voltage control device for a vehicle alternator, which is supplied to the switching means.